Effect of Heat Treatment in the Atmosphere on Hydrophilization of Microporous Carbon Electrode and Impregnation of Electrolyte Solutions

Abstract

To improve the power density of an enzymatic biofuel cell, it’s necessary to promote the impregnation of electrolyte solutions into the microporous carbon electrode and to enlarge the reaction interface. In this study, the high-temperature heat-treatment of microporous electrodes composed of Ketjenblack (KB) was performed in the atmosphere, and the hydrophilic properties were imparted to the KB layers by the functional groups. The wettabilities of the heat-treated microporous layers were evaluated based on X-ray photoelectron spectroscopy (XPS) and the contact angle measurement. In addition, their pore structures and specific surface areas were investigated by the BET nitrogen adsorption method. The cyclic voltammetric (CV) measurements revealed that the heat-treatment of KB layers improves the impregnation of electrolyte solutions into the microporous electrodes.